the problem that I’m having, is that after adding the domain to the subdomain directory, visiting the domain page displays a file directory instead of the webpage, in other words the index.html file does not display the webpage automatically, in order for me to display the webpage I have to literally input http://domain.com/index.html
Sorry if this is a side issue, but I don’t get why, if you own domain.com, you are bothering with subdomain.domain.com. Perhaps I’m missing something, but it sounds odd.
Anyhow, it does sound odd that you are seeing a directory. You are sure index.html is actually in there and not somewhere else? Looks like index.html is in the root folder of domain.com but not in the root folder of subdomain.domain.com. But I don’t really understand your setup anyway.